Non-invasive, affordable home test for cancer will undergo clinical trials this year and could be for sale soon

In only four years, a saliva test that detects cancer could be available to buy from pharmacies in the U.K., which could potentially save thousands of lives by detecting the disease in its very early stages.

Professor Wong spoke about the so-called "liquid biopsy" at the American Association for the Advancement of Science’s annual meeting in Washington.

Patients who buy the test, which would cost around £15, would have to send a small amount of saliva to a laboratory, where it would be analysed to see if it contained fragments of tumour DNA.

Professor Wong revealed that the test is to undergo full clinical trials later this year.

"If there is [a] circulating signature of a tumour in a person's blood or saliva, this test will find it," he said. "We need less than one drop of saliva and we can turn the test around in 10 minutes. It can be done in a doctor’s office while you wait. Early detection is crucial."

Right now in the U.K., a blood test or tissue sample is used to diagnose cancer and the results can take up to two weeks to come back.

So far, the test has been trialled on lung cancer patients with "near-perfect" accuracy, however Professor Wong thinks it could be successful in detecting other types of cancer, such as pancreatic cancer, which has no "effective early screening capabilities".

Dr Áine McCarthy, Cancer Research UK’s science information officer, told Huffington Post: "Developing new techniques to diagnose cancer earlier is an important part of global efforts to tackle the disease. Detecting tell-tale signs of cancer in blood, saliva or urine, instead of taking tissue samples, is one area that’s showing a lot of promise and could speed up diagnosis. Researchers are working to get these tests ready for routine use — it’s crucial to understand how accurate they are and how doctors can best use them alongside current scans and tests."

Warning signs of cancer you should never ignore

Sudden weight loss when not dieting

Blood in your faeces or urine

Coughing up blood

A lump in the breast, groin, testes, side of the neck or armpit

Severe, unexplained pains or aches

Indigestion or difficulty swallowing

Obvious change in the size, colour, shape or thickness of a wart, mole or mouth sore